35 research outputs found
Sharksucker (Echeneis naucrates) on a Bottlenose Dolphin (Tursiops truncatus) from Sarasota Bay, Florida, with Comments on Remora-Cetacean Associations in the Gulf of Mexico
Distribution of Molidae in the Northern Gulf of Mexico
We compiled all available sighting, stranding and bycatch data for the Family Molidae (molas) in the northern Gulf of Mexico (NGOM) to assess spatial and temporal distribution. Overall, 483 records were collected from shipboard and aerial surveys, fisheries bycatch, and strandings. Molas were recorded year-round, with a ubiquitous distribution in both nearshore and offshore waters. Ocean sunfish (Mola mola) were sighted with greatest frequency during the winter (December thru April) in sea surface temperature \u3c 24° C. Potential reasons for increased sightings during winter may be related to the lack of a well-defined thermocline in the NGOM; the species\u27 basking behavior associated with thermoregulation; and oxygen replenishment after long, deep dives to oxygen-deficient depths
An Unusual Reaction and Other Observations of Sperm Whales Near Fixed-Wing Aircraft
Reported behavioral reactions by sperm whales to aircraft are sparse, highly variable, and largely anecdotal as summarized below. Observers since the whaling era began have noted that sperm whales tend to be skittish (Whitehead 2003). When documented, sperm whale reactions to both planes and helicopters range from no reaction (Clarke 1956, Gambell 1968, Green et al. 1992) to reactions such as increased surface intervals and dramatic behavioral changes (Clarke 1956, Fritts et al. 1983, Mullin et al. 1991, WuÌrsig et al. 1998, Richter et al. 2003, 2006). Given the lack of supporting data for either case, it is important that these types of data are collected and consolidated into a cohesive document. Therefore, the specific objectives of our paper are to report our visual observations of sperm whale reactions to straight-line aircraft fly-bys (i.e., passes), to report a unique observation of a recognized âstress behavioral reactionâ exhibited by sperm whales during an overhead circling by small fixed-wing aircraft, and to provide a summary review of published related studies
Polar Bear (Ursus maritimus) Behavior near Icebreaker Operations in the Chukchi Sea, 1991
Increasing interactions of polar bears (Ursus maritimus) with human activity, combined with impacts of climate change, are of critical concern for the conservation of the species. Our study quantifies and describes initial reactions and behaviors of polar bears observed from an icebreaker during summer 1991 at two exploratory drilling sites (near sites drilled in 2015) located in the Chukchi Sea 175 km and 312 km west of Barrow, Alaska. Polar bear behavior was described using continuous sampling of six predetermined focal group behavior states (walking, running, swimming, resting, feeding or foraging, unknown) and six behavioral reaction events (no reaction, walking away, running away, approaching, vigilance [i.e., watching], unknown). Forty-six bears in 34 groups were monitored from the Robert LeMeur (an Arctic Class 3 icebreaker) for periods of five minutes to 16.1 hours. Significantly more bear groups reacted to icebreaker presence (79%) than not (21%), but no relationship was found between their reactions and distance to or activity of the icebreaker. Reactions were generally brief; vigilance was the most commonly observed reaction, followed by walking or running away for short (< 5 minutes) periods and distances (< 500 m). Eleven percent of bear groups approached the vessel. No significant difference was found between reactions when cubs were present and those when cubs were absent. Despite the limited sample sizes, these findings are relevant to assessing potential impacts of resource development and shipping activities on polar bears, especially given the sparsity of such information in the face of growing human activity in the Arctic offshore areas. Overall, climate change is leading to longer and more extensive open-water seasons in the Arctic and therefore to increasing marine trafficâmore vessels (including icebreakers) for a longer time each year over a wider area. Les interactions de plus en plus grandes entre les ours polaires (Ursus maritimus) et lâactivitĂ© humaine, alliĂ©es aux incidences du changement climatique, constituent une prĂ©occupation critique en matiĂšre de conservation de lâespĂšce. Notre Ă©tude permet de quantifier et de dĂ©crire les rĂ©actions et les comportements initiaux des ours polaires observĂ©s Ă partir dâun brise-glace Ă lâĂ©tĂ© 1991 Ă deux sites de forage dâexploration (prĂšs de chantiers forĂ©s en 2015) dans la mer des Tchouktches, Ă 175 km et Ă 312 km Ă lâouest de Barrow, en Alaska. Le comportement des ours polaires a Ă©tĂ© dĂ©crit en recourant Ă lâĂ©chantillonnage en continu de six Ă©tats de comportement prĂ©dĂ©terminĂ©s pour le groupe ciblĂ© (marcher, courir, nager, se reposer, manger ou chercher de la nourriture et comportement inconnu) et de six rĂ©actions comportementales aux Ă©vĂ©nements (aucune rĂ©action, sâen aller Ă la marche, sâen aller Ă la course, sâapprocher, faire preuve de vigilance [câest-Ă -dire observer], rĂ©action inconnue). Quarante-six ours faisant partie de 34 groupes ont Ă©tĂ© surveillĂ©s Ă partir du Robert LeMeur (un brise-glace de lâArctique de classe 3) pendant des pĂ©riodes allant de cinq minutes Ă 16,1 heures. Fait important, plus de groupes dâours ont rĂ©agi Ă la prĂ©sence du brise-glace (79 %) que pas rĂ©agi (21 %), mais aucune relation nâa pu ĂȘtre Ă©tablie entre leurs rĂ©actions et la distance ou lâactivitĂ© du brise-glace. De maniĂšre gĂ©nĂ©rale, les rĂ©actions Ă©taient brĂšves. La vigilance Ă©tait la rĂ©action la plus souvent observĂ©e, suivie du fait de sâen aller en marchant ou de sâen aller Ă la course pendant de courtes (< 5 minutes) pĂ©riodes et distances (< 500 m). Onze pour cent des groupes dâours se sont approchĂ©s du vaisseau. Aucune diffĂ©rence importante nâa Ă©tĂ© relevĂ©e entre les rĂ©actions, quâil y ait des oursons ou non. MalgrĂ© la taille restreinte des Ă©chantillons, ces constatations ont de la pertinence dans lâĂ©valuation des incidences potentielles des activitĂ©s de mise en valeur et de transport des ressources sur les ours polaires, surtout compte tenu de la raretĂ© de telles donnĂ©es Ă la lumiĂšre de lâactivitĂ© humaine croissante dans les zones extracĂŽtiĂšres de lâArctique. Dans lâensemble, le changement climatique mĂšne Ă des saisons navigables plus longues et plus Ă©tendues dans lâArctique. Par consĂ©quent, le trafic maritime sâaccentue en ce sens quâil y a plus de vaisseaux (brise-glace y compris) pendant de plus longues pĂ©riodes chaque annĂ©e, sur de plus grandes surfaces
Occurrence, movements, and behavior of bottlenose dolphins (Tursiops truncatus) in association with the shrimp fishery in Galveston Bay, Texas
Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to [email protected], referencing the URI of the item.Includes bibliographical references.Not availabl
Behavioral responses of bottlenose dolphins to remote biopsy sampling and observations of surgical biopsy wound healing
Information on reactions of delphinids to biopsy sampling and healing of associated biopsy wounds is limited. Results presented here report on the behavioral responses of free-ranging bottlenose dolphins (Tursiops truncatus) to remote biopsy sampling procedures, and provide information on stages of surgical biopsy wound repair. Biopsy samples of free-ranging dolphins were collected between FebruaryâMay 1992 in Galveston Bay, Texas, using a sterilized corer-tipped bolt, launched from a crossbow. A total of 8 direct âhitsâ were documented, 4 hits (50%) in which a tissue sample was obtained, 2 hits (25%) from which no sample was retrieved, and 2 hits (25%) in which the bolt struck the water (within approximately 30â60 cm) prior to striking the animal (no samples). Behavioral reactions were similar for all eight dolphins directly struck by a bolt, and were best characterized as startle responses. As part of a NMFS sponsored capture effort to assess a 1992 bottlenose dolphin die-off in Matagorda Bay, Texas, surgical biopsy samples were taken from 35 dolphins (Sweeney, 1992). Biopsies roughly 3â5 cm in diameter and 1 cm deep, were surgically removed. While surgical biopsy wounds were not identical to remote biopsy wounds, they were comparable. Sixteen of the 35 surgically biopsied individuals were photographically resighted between July 1992 and December 1993. Photographs of biopsies immediately after completion of surgical procedures and up to 476 days post-biopsy were classified into four stages of healing. Epidermis appeared to have covered wounds by 40â42 days post-biopsy, but in some cases possibly as early as 15â26 days. Repigmentation of epidermal tissue varied between individual dolphins, but in no cases occurred prior to 61 days post-biopsy. No indication of infection or related pathologies were detected from any of the biopsy wounds monitored during this study. Findings reported here suggest that when adequate care and caution are used, biopsy sampling of bottlenose dolphins is not likely to produce long-term behavioral alterations or result in physiological complications during wound healing
A review of marine mammal records of Cuba
There has been very little research on marine mammals in Cuban waters. Much of the information on marine mammals in this region is buried in historical and gray literature. In order to provide a comprehensive account of marine mammal occurrence in Cubaâs Exclusive Economic Zone (EEZ), we reviewed and verified 659 published and unpublished sighting, stranding, capture, and tagging records. Eighteen extant species and four genera have confirmed records for Cuban EEZ waters. This includes 17 species of cetaceans (three baleen whales and 14 toothed whales) and one sirenian species. An additional 11 cetacean species and one extant pinniped species have been reported, but not confirmed, or may have the potential to occur in Cuban waters. Historical records of the Caribbean monk seal (Monachus tropicalis) are documented in Cuba; however, this species is now considered extinct. The only two species that are seen regularly and considered common in Cuban nearshore waters are the common bottlenose dolphin (Tursiops truncatus) and the West Indian manatee (Trichechus manatus)